Orioles catcher Welington Castillo on Wednesday tried to downplay the connection between the shoulder tendinitis that landed him on the disabled list this week and his participation in the World Baseball Classic, where he caught for the Dominican Republic and played through pain while doing it.

During spring training, he had a neck problem early in Grapefruit League action that the team now thinks was related to this shoulder trouble. Castillo believes it would have been able to heal in a normal March, when he was only catching Grapefruit League games, but instead he wanted to represent his country.

“Honestly, I feel like the same thing that I had in spring training, just getting worse,” Castillo said. “I was playing through that all of spring training, all of the WBC until now. I think the body is just telling me I can’t continue to go farther than this. But honestly, after medication, I feel a lot better. I hope that I can come back soon to help the team win.”

Castillo has been fine at the plate, batting a team-high .314 in 17 games, but the problem would grow worse as games progressed and really bothered him after games. He and manager Buck Showalter, without specifically blaming the WBC, where Castillo caught for the Dominican Republic, said it was just an issue of too much, too soon.

“I think so,” Castillo said. “You as a professional baseball [player], you know the right time and what to do to get your arm and your body in game shape. But at the WBC, I don’t blame it on the WBC because it was my decision to play there. But you take step, I think, going to the WBC. Your body, your arm, it’s not where you want it to be, 100 percent. And I think you force it and cause stuff like that. Honestly, I don’t blame it on the WBC. I had that before and it doesn’t feel any better, but the good thing is I’m taking care of it and it’s not going to take a long time, either.”

Showalter said he expects Castillo to be available May 11, the first day he’s eligible to come off the disabled list.

“He’s in his third day into the dose pack that takes about five or six days,” Showalter said. “He already feels a little bit better. Anytime you start a clock early on these guys with the WBC and stuff, he was wanting to catch the first game of the intrasquad game and you could tell how much he wanted to be ready to start for the Dominican. I’m not thinking it might have a little something to do with that, too. But God forbid it’s something we did, right? There’s probably a lot of factors.”

Tillman on track for weekend return: Showalter said after Tuesday’s game that right-hander Chris Tillman would be the team’s starter Sunday against the Chicago White Sox barring any weather problems that changes the rotation.

However, Showalter was less specific Wednesday about where Tillman fits in.

“Chris went well [Tuesday] night,” the manager said. “He’s going to meet us in Baltimore on Friday, which is his workday. No sense in flying here for one day, so he’ll meet us there and take his workday Friday and decide where we’re going to plug him in.”

Peña still up: Catcher Francisco Peña, who joined the Orioles on Tuesday as a backup catcher to play behind Caleb Joseph in Castillo’s place, is glad for the chance to be in the majors again.

Peña was designated for assignment during the offseason but remained in the organization, and was hitting .290 with a home run in 10 games for Triple-A Norfolk when he was added to the roster.

“It’s fun to be back,” Peña said. “It’s not the circumstance that you wanted, to see one of your teammates getting hurt. But I’m happy to be here, just ready to go and ready to help the team however they need me.”

While in Norfolk, Peña was charged with shepherding a young rotation that features some promising arms. He took pride in that role and helping the likes of Chris Lee and Gabriel Ynoa settle in after rocky starts.

“I think being there, I think it’s my fourth year in Triple-A, it makes it a little easier helping them, trying to guide them on what to do,” Peña said. “Honestly, what I tell them is it’s the same game. Different level, but the same game. And once you go go across those white lines, it’s time to have some fun.”

Around the horn: The Red Sox announced Wednesday that a fan who used a racial slur toward another fan during Tuesday's game was ejected from the stadium and "since been notified they are no longer welcome at Fenway Park." The organization had pledged zero-tolerance after Orioles center fielder Adam Jones was the target of racist taunts from the stands on Monday. ... Right-hander Kyle Kendrick will start Thursday for the Red Sox in place of knuckleballer Steven Wright, who is on the disabled list with a knee injury. Kendrick has not made a major league start since 2015. … Outfielder Chris Dickerson, who is at Triple-A Norfolk, went on the disabled list with an oblique strain.